The present invention relates to a nozzle for separating a representative sample from a gas mixture which contains a finely divided solid, in order to analyze the sample, the nozzle having a sample-taking mouth opening into the sample-taking chamber and a conduit connected to it, for separating a sample and for directing it to analysis, and a second conduit for feeding liquid into the said sample-taking mouth in order to clean it and to mix the liquid with the gas sample.
Previously known is an oxygen analyzer provided with a so-called rotating spray probe, in which the probe consists of a pipe opening into the sample-taking space and equipped with a water-cooled mantle, and in which there is additionally a second pipe for feeding water from the tip of the probe in the direction of the gas sample, mixed with the sample. Water is sprayed in front of the sample-taking pipe, whereupon part of the water is mixed with the sample gas flowing into the probe and part of it washes the mouth of the probe clean of the dust which had adhered to it. Thus such a probe cannot be used for absorbing solid or gas into water when it is desired to make a quantitative analysis of the gas or solid content of the gas sample or suspension. The purpose of the water spray used in the sample-taking probe of such an oxygen analyzer is only to keep the mouth of the sample-taking pipe open when a sample is being taken from dust-bearing flue gases. The concentration of oxygen is measured from a dried and purified gas sample, in which case the quantity of the water used for keeping the sample-taking probe open is not signficant with respect to the analysis.
The object of the present invention is thus to provide a nozzle for separating a representative sample from a dust-bearing gas for analysis, the nozzle having a sample-taking mouth opening into the sample-taking chamber, and a conduit connected to it for separating the sample and for directing it to analysis, and a second conduit for feeding a liquid, preferably water, into the said mouth of the sample-taking pipe in order to keep it clean and to mix the liquid with the gas sample, all the washing liquid being recovered carefully so that the solid and gaseous constituents dissolved in it from the gas can be analyzed quantititively. Since the analysis is carried out on the washing liquid, and not on the dried and purified gases as in the above-mentioned prior known sample-taking appartus, it is very important that all of the washing liquid is recovered quantitatively while ensuring that the sample-taking probe remains open.
In the specification and patent claims of the Application, by the analysis of the gas mixture which contains a possibly dust-containing solid is meant the analysis of the gaseous components of the gas mixture and/or its various solid constituents in dust-like form. By the gas mixture, respectively, is meant a combination which contains at minimum two gaseous substances or at minimum one gaseous substance and at minimum one solid.